JPS6242644A - Communication controller - Google Patents

Abstract

PURPOSE:To perform well-balanced transmission and reception operations without any bias by transmitting and receiving transmission data and reception data alternately when transmission data and reception data exist together. CONSTITUTION:When transmission data is generated in a central processing unit (CPU) 1, a communication controller 10 is interrupted through a line 13, and a transmission processing part 18 transmits transmission data 1 to a data transmitting and receiving device 12 of the other party if this interruption is concerned with the transmission processing. When transmission data 2 exists, the similar processing is performed. This processing is repeated until all transmission data are transmitted. If data is received from the device 12 during the processing of transmission data 2, the control is transferred to a reception reporting part 20 whose interruption level is higher than that of the transmission processing part 18. Then, reception data is connected to a reception processing part 19, and the communication controller 10 is restored from the interruption immediately to process transmission data 2, and the control is transferred to the reception processing part 19. The reception processing part 19 checks the existence of a reception data queue, and reception data is transferred to the CPU side if it exists.

Description

[Detailed Description of the Invention] [Summary] If the communication control device has only either transmission data or reception data, the data continues to be sent from the communication control device, but during transmission or reception, When reception data or transmission data is generated, the transmission processing means and the reception processing means are caused to perform alternate transmission and reception in response to the occurrence of reception data or transmission data, so that balanced transmission and reception processing can be performed.

[Industrial application field]

The present invention relates to a communication control device, and more specifically, to a communication control device equipped with means for balancing transmission and reception processing.

In a data communication system, a central processing unit (hereinafter referred to as C
It is abbreviated as PU. ) is connected to the other party's data transmitting/receiving device via a communication control device to perform data communication, such as a LAN (local area network).
There is.

In such a system, when a large amount of data is transmitted, balance may be required between the transmitted and received data in order to smoothly carry out the data communication process.

[Conventional technology]

A conventional communication control device for transmitting and receiving data between a CPU side and a data transmitting/receiving device of the other party was configured as follows.

When data to be sent to the CPU occurs, the CPU issues an interrupt to the communication control device. The communication control device that received the interrupt request analyzes the interrupt cause, and if the interrupt factor is related to data transmission, the data is transferred from the communication control device to the other party. The data is sent to the data transmitting/receiving device.

When receiving data from the other party's data transmitting/receiving device, if an interrupt occurs in the reception processing unit in the communication control device indicating that the data has been received, and the CPU side is in a state where it can receive or receive data, the CPU side receives the data. The data is transferred, and the communication control device sends a received data transfer end interrupt to the CPU to end the data reception.

[Problem that the invention seeks to solve]

Since the transmission processing and reception processing in the communication control device described above are performed independently, the following problem occurs.

If transmission processing and reception processing are performed at the same processing order level, the imbalance between transmission and reception will become a problem and will not be taken into consideration if there is not much transmission data or reception data. However, when transmitting or receiving a large amount of data, a situation arises in which only the transmitting process is performed and no receiving process is performed even if there is received data. In addition, in the case of reception,
Conversely, it may become difficult to perform the transmission process.

Furthermore, if the transmission processing order level is set higher than the reception processing order level, the transmission processing will be performed preferentially, and if there is a large amount of transmission data, the reception processing will not be performed easily.

On the contrary, if the reception processing priority level is made higher than the transmission processing priority level, the opposite situation will occur when the transmission processing priority level is made higher than the reception processing priority level.

The present invention was created in view of the above-mentioned problems, and an object of the present invention is to provide a communication control device that can perform balanced transmission and reception processing.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the present invention. In this figure, reference numeral 1 denotes a communication control device that controls data transmission and reception between a first data transmission and reception device 2 and a second data transmission and reception device 3. This communication control device 1 includes a data transmission processing means 4 for transmitting data from a data transmitting/receiving device on the transmitting side to a data transmitting/receiving device on the receiving side, and a data transmitting/receiving device from the data transmitting/receiving device on the receiving side to the data transmitting/receiving device on the transmitting side. a data reception processing means 5 for receiving data, and a control means 6 for causing the transmission processing means and the reception processing means to operate alternately in response to generation of reception data or transmission data during transmission or reception. It is provided as the main part.

[Effect]

First data transmitting/receiving device 2 and second data transmitting/receiving device 3
When received data or transmitted data is generated while data is being transmitted or received between them, the control means 6 responds to the occurrence and causes the transmitting processing means 4 and the receiving processing means 5 to perform the same operation alternately. Close.

Due to such alternating transmission and reception operations, no imbalance occurs in the transmission and reception operations, so that balanced transmission and reception processing can be performed.

〔Example〕

FIG. 2 shows an embodiment of the invention. In this figure, 1
0 is the communication control unit and this is the central processing unit (CPU) 11
It controls data transmission and reception between the data transmission and reception device 12 of the other party. 13 is a line for an interrupt signal from CPUII, and 14 is a line for an interrupt request signal to CPUI1. 15 is a bus for transferring data. 16 is a data transmission line, and 17 is a data reception line. 18, 19, 20, and 21 are a transmission processing section and a reception processing section provided in the communication control device 10, respectively.

This is a reception notification section and a buffer. The transmission processing section 18 and the reception processing section 19 are configured to be activated by an interrupt from the CPU10, and the reception notification section 20 is activated when data is received from the data transmission/reception device 12 on the other side. It is configured to operate with a higher priority than the transmission processing section 18 and the reception processing section 19. The buffer 21 temporarily stores received data as a received data queue.

The operation of the apparatus of the present invention configured as described above will be explained below.

When transmission data is created in the CPU II, the CPU
II interrupts the communication control unit 10 via line 13. The communication control device 10 that received this interrupt analyzes the cause of the interrupt, and if the interrupt is related to transmission processing, the transmission processing unit 18 receives and receives the transmission data 1 from the CPU11 and transmits it to the data transmission/reception device 12 on the other side. . If transmission data 2 exists, similar processing is performed. Such processing is repeated until there is no more data to send.

When data is received from the other party's data transmitting/receiving device 12 during the transmission process of the transmission data 2 as described above, control is transferred to the reception notification section 20 whose interrupt level is higher than that of the transmission processing section 18 . When the reception notification section 20 connects the received data to the reception data queue of the reception processing section 19, it immediately returns from the interrupt and when the processing for the transmission data 2 is completed, control is transferred to the reception processing section 19. The reception processing unit 19 checks the existence of the reception data queue, and if there is reception data there, removes one piece of reception data from the reception data queue and transfers the reception data to the CPU side.

Then, when data is received from CPU 1 in a state where there are no interrupts, the reception notification unit 20 is activated in this case as well, and after the received data is connected to the reception data queue, an interrupt request is issued to CPU 1. . The CPU 1 that receives the interrupt request issues an interrupt to the communication control device 10 . When this interrupt occurs,
Since there is no transmission request, the transmission processing section 18 performs no processing and control is transferred to the reception processing section 19. Since the receive data queue exists, the received data is transferred to CPUI1.

As described above, when transmission and reception data exist, transmission processing and reception processing occur alternately. Therefore, data reception processing can be performed even when a plurality of transmission data are being processed, and transmission requests from the CPU can be accepted even when a large amount of reception data is being received. This makes it possible to perform balanced data transmission and reception.

In the above embodiment, a case has been described in which a data queue is provided only on the receiving side, but a configuration may also be adopted in which a data queue is provided on the transmitting side as well.

Further, the present invention can also be applied to communication control devices used in systems other than the system configuration described above.

〔Effect of the invention〕

As described above, according to the present invention, when transmission data and reception data coexist, the data are alternately transmitted and received, so that balanced transmission and reception processing can be performed.

[Brief explanation of drawings]

Figure 1 is a block diagram of the principle of the present invention. FIG. 2 is a diagram showing an embodiment of the present invention. In Figures 1 and 2, 1 is a communication control device; 2.3 is a data transmitting and receiving device, 4 is a transmission processing means; 5 is a reception processing means; 6 is a control means; 21 is a buffer.

Claims (2)

[Claims] (1) In a communication control device (1) that controls data transmission and reception between a first data transmitting/receiving device (2) and a second data transmitting/receiving device (3), from the data transmitting/receiving device on the transmitting side to the receiving side. a data transmission processing means (4) for transmitting data to a data transmission/reception device serving as a receiver; and a data reception processing means (5) for receiving data from a data transmitting/receiving device serving as a receiving side to a data transmitting/receiving device serving as a transmitting side; , control means (6) for causing the transmission processing means (4) and the reception processing means (5) to perform their operations alternately in response to the generation of reception data or transmission data during transmission or reception;
A communication control device comprising: (2) The control means is assigned a higher interrupt level than the transmission processing means (4) and the reception processing means (5), and the control means is assigned a higher interrupt level than the transmission processing means (4) and the reception processing means (5), and the reception processing means for the reception data responds to an interrupt caused by the generation of reception data during transmission. characterized in that it is configured to cause the sending data to be alternately sent out and the received data in the receive data queue store (21) after causing the storage in the receive data queue store (21) in the receive data queue store (21). A communication control device according to claim 1.